Giant Hogweed

Warnings have been issued for southern Ontario regarding giant hogweed (Heracleum mantegazzianum) aka giant cow parsley.  This is a  perennial, invasive noxious weed that reaches a height of 5 metres is a public health risk.  The sap contains furocoumarin, a chemical that renders skin extremely susceptible to UV exposure resulting in severe burns and blistering (phytophotodermatitis).  This can